cel and c12 code
Thread Starter
Racer
Joined: Mar 2008
Posts: 326
Likes: 20
cel and c12 code
1995 coupe 6sp
Well guys, another post. This has been going on for awhile, had a bunch of history codes last time and all I really got was low voltage may be causing the issue. Soooo months go by and I finally replaced the battery, which was probably fine, the brake lights stayed on and killed it over night. Didn't notice till I hooked the new battery up.( But hey its a c4, if you don't have 100$ you can flush down a toilet then you shouldn't own one!)
Soo I say great maybe the cel won't come on now. Go a day and it's back on. Generally happens if I shut the car off and restart it, if I go straight to work and straight home it's fine.
So I do the whole shove your head into the foot well with your *** sticking up and knees about to give out thing to short pin 4 to 12 and I get a nice c12 code and I'm fairly sure I heard "go screw yourself " come out of the speakers.
I dunno, where do you start when a cel comes on constantly but you get no code?
Cooling fans go to high still too when the cel comes on.
Thoughts?
Well guys, another post. This has been going on for awhile, had a bunch of history codes last time and all I really got was low voltage may be causing the issue. Soooo months go by and I finally replaced the battery, which was probably fine, the brake lights stayed on and killed it over night. Didn't notice till I hooked the new battery up.( But hey its a c4, if you don't have 100$ you can flush down a toilet then you shouldn't own one!)
Soo I say great maybe the cel won't come on now. Go a day and it's back on. Generally happens if I shut the car off and restart it, if I go straight to work and straight home it's fine.
So I do the whole shove your head into the foot well with your *** sticking up and knees about to give out thing to short pin 4 to 12 and I get a nice c12 code and I'm fairly sure I heard "go screw yourself " come out of the speakers.
I dunno, where do you start when a cel comes on constantly but you get no code?
Cooling fans go to high still too when the cel comes on.
Thoughts?
Team Owner
Joined: Feb 2003
Posts: 54,110
Likes: 9,424
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
C12 with the engine turned off and the key is on is a telling you there is no cranking single to the ECM from the opti.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
If there were codes they were erased when battery was replaced. The 12 indicated ECM is alive and engine not running. When terminals are shorted codes display long with ECM controlled "Stuff" will be energized. Except for the early CCC cars (electric carb) only the lack of a code 12 (no codes display) would be diagnosed. So you should have no worries.
Thread Starter
Racer
Joined: Mar 2008
Posts: 326
Likes: 20
Right c12 means everything is fine.
Problem is since I've replaced the battery I've seen the cel probably 5-7 times and driven with it on for 30 minutes and I still get no stored codes.
Car runs fine btw. The cooling fans just come on when the cel does.
Problem is since I've replaced the battery I've seen the cel probably 5-7 times and driven with it on for 30 minutes and I still get no stored codes.
Car runs fine btw. The cooling fans just come on when the cel does.
Team Owner
Joined: Feb 2003
Posts: 54,110
Likes: 9,424
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
The fans are to supposed to come on with the light. I never had any luck with the paper clip method. Find your self or find someone with a good scan tool and your find your answer
Team Owner
Joined: Feb 2003
Posts: 54,110
Likes: 9,424
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Thread Starter
Racer
Joined: Mar 2008
Posts: 326
Likes: 20
My update for future searches, since Noone really does that.
Been since halloween that I replaced the battery. It seems it took a couple days for the car to get used to the new battery. Haven't seen the cel for awhile even with shutting it off and on. I think it's fixed and possibly low voltage was the cause? I also hooked my factory radio back up, but I did have another factory radio in it after replacing the battery and got cel multiple times.
Fingers crossed it's fixed.
Been since halloween that I replaced the battery. It seems it took a couple days for the car to get used to the new battery. Haven't seen the cel for awhile even with shutting it off and on. I think it's fixed and possibly low voltage was the cause? I also hooked my factory radio back up, but I did have another factory radio in it after replacing the battery and got cel multiple times.
Fingers crossed it's fixed.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski